1. Field of the Invention
The present invention relates to a pharmaceutical composition, and more specifically to a fast dissolving tablet and method of preparing the same.
2. Description of the Related Art
There are various types of oral administrative medicines, such as, tablets, capsules, granules, powders, syrups and the like. Orally administrated medicines, however, suffer from many drawbacks. Tablets and capsules, for example, may be difficult to swallow for the elderly or children. Granules and powders, may leave an unpleasant taste after dosage or possibly enter the respiratory tract or lungs, additionally, dosage of syrups, may be difficult measured, particularly for the elderly or children.
Therefore, many researches regarding fast dissolving tablets has been undertaken recently to provide a new generation rapidly dissolved and safely swallowed tablets, and their dose can be accurately measured. The tablets must additionally possess adequate hardness to facilitate the packaging process.
Several related arts are disclosed as follows. Japanese Patent No. 76420/1977 and 24410/1983 describe a method of preparing a porous tablet which comprises blending a tablet-constituting composition with inert solvent, solidification, compressing the resulting solid into tablets, and evaporating solvent by freeze-drying. U.S. Pat. No. 5,501,861 discloses a method of preparing a fast dissolving tablet comprising a water-soluble saccharide (such as sugar, starch, lactose, sugar alcohol, or tetrose) and a pharmacologically active ingredient, which comprises compressing the blended solid into tablets with molding pressure of 5˜130 kg/cm2 and evaporating solvent by freeze-drying.
The above fast dissolving tablets are prepared by Zydis freeze-drying (from R. P. Scherer, England). This method, however, suffer from high process cost and insufficient mechanical strength of the preparation.
Japanese Patent No. 15830/1986 describes a method of preparing a porous tablet which comprises blending a pharmaceutically active ingredient with an antacid having a porous and extra fine crystal structure. The composition described in this patent is prepared by heating and melting the ingredients, so that it is inferior in the scope of compatible medicament and disintegrating ability of the preparation in an oral cavity.
European Patent No. 0914818 discloses a fast dissolving tablet comprising sugar alcohol or saccharide, a disintegrant, and a pharmaceutically active ingredient. The hardness of the tablet, however, is only 3 NT, and does not satisfy generally packaging requirements.
Therefore, it is necessary to develop a preparation which offers acceptable disintegration speed in an oral cavity and possesses a sufficient mechanical strength so as to protect the preparation from destruction in the course of manufacture.